@Transactional注解有两个，一个是spring提供的@org.springframework.transaction.annotation.Transactional 另一个是jdk提供@javax.transaction.Transactional。在回滚的设置上，spring提供的是rollbackFor，jdk提供的是rollbackOn，在使用方法上是一致的。
这两个注解在我有限的测试里表现是一样的。

用在哪里

@Transactional注解既可以写在方法上也可以写在类上。写在类上则这个类的所有public方法都将会有事务。这样显然会使一些不需要事务的方法产生事务，所以更好的做法是在想要添加事务的方法上标注@Transactional。

rollbackFor

@Transactional的rollbackFor用于指定能够触发事务回滚的异常类型，可以指定多个，用逗号分隔。
rollbackFor默认值为UncheckedException，包括了RuntimeException和Error.
当我们直接使用@Transactional不指定rollbackFor时，Exception及其子类都不会触发回滚。

public class BusinessException extends Exception {
    public BusinessException(String msg) {
        super(msg);
    }
}

@Autowired
    private UserRepository userRepository;
    
    // 不回滚
    @Transactional
    public void test1() throws Exception {
        User user = new User(1, "15000000000", "d243ewa", "Comma");
        saveUser(user);
        throw new Exception("test1 error");
    }

    // 不回滚
    @Transactional
    public void test11() throws Exception {
        User user = new User(1, "15000000000", "d243ewa", "Comma");
        saveUser(user);
        throw new BusinessException("test11 error");
    }

    // 回滚
    @Transactional(rollbackOn = Exception.class)
    public void test2() throws Exception {
        User user = new User(1, "15000000000", "d243ewa", "Comma");
        saveUser(user);
        throw new Exception("test2 error");
    }

    // 回滚
    @Transactional(rollbackOn = Exception.class)
    public void test21() throws Exception {
        User user = new User(1, "15000000000", "d243ewa", "Comma");
        saveUser(user);
        throw new BusinessException("test21 error");
    }

    // 回滚
    @Transactional
    public void test3() {
        User user = new User(1, "15000000000", "d243ewa", "Comma");
        saveUser(user);
        throw new RuntimeException("test3 runtime error");
    }

    // 不回滚
    @Transactional
    public void test4() throws Exception {
        User user = new User(1, "15000000000", "d243ewa", "Comma");
        test41(user);
        throw new Exception("test4 error");
    }

    @Transactional(rollbackOn = Exception.class)
    public void test41(User user) {
        saveUser(user);
    }

    // 不回滚
    public void test5() throws BusinessException {
        test6();
    }

    // 回滚
    @Transactional(rollbackOn = Exception.class)
    public void test6() throws BusinessException {
        User user = new User(1, "15000000000", "d243ewa", "Comma");
        saveUser(user);
        throw new BusinessException("test6 error");
    }

    // 回滚
    @Transactional(rollbackOn = Exception.class)
    public void test7() throws BusinessException {
        test8();
    }

    public void test8() throws BusinessException {
        User user = new User(1, "15000000000", "d243ewa", "Comma");
        saveUser(user);
        throw new BusinessException("test8 error");
    }

    public User saveUser(User user) {
        return userRepository.save(user);
    }

有一点需要注意，在service中间接调用的方法不会触发事务